1. Field of the Invention
This invention relates generally to apparatus for recording and/or reproducing information signals and, more particularly, is directed to a mechanism for loading and unloading a magnetic tape cassette into and from apparatus for recording and/or reproducing information signals.
2. Description of the Prior Art
Apparatus for recording and/or reproducing information signals from a magnetic tape disposed in a tape cassette are well-known in the art. Such apparatus generally includes a mechanism for loading and unloading the tape cassette into and out of operative engagement with a tape drive mechanism, whereby the magnetic tape in the cassette is longitudinally advanced past a magnetic recording/reproducing head. Generally, the cassette loading and unloading mechanism includes a cassette holder into which the cassette is disposed and which is adapted to occupy a first loading position and a second operative position. When the cassette holder is in its loading position, the tape cassette can be inserted into the holder or ejected therefrom, and when the cassette holder is in its operative position, the tape cassette is firmly held therein to be engaged by the tape drive mechanism which may be comprised of a capstan drive assembly and two reel drive shafts. In particular, when the cassette holder, and thereby the tape cassette, are moved into the operative position, the reel drive shafts engage with the reels of the cassette and the capstan drive assembly enters corresponding openings provided in the cassette to engage with the tape therein.
Examples of known cassette loading and unloading mechanisms are disclosed in U.S. Pat. Nos. 3,752,488 and 3,904,149. In these latter mechanisms, a locking arm normally engages and retains the cassette holder in the first loading position. The locking arm is disengaged from the cassette holder by the tape cassette which is inserted therein and, at such time, the cassette holder, which is no longer restrained, is biased by a spring connected thereto into its operative position. With the above arrangement, the locking arm is pivotally mounted to a fixed chassis for engaging with and disengaging from the cassette holder. However, because of slight differences in size between different cassette holders, errors may result in the position at which the locking arm disengages from the cassette holder. Accordingly, with such mechanisms, the locking arm is generally constructed to provide an allowance in the position at which it is pivoted to the chassis. This allowance, however, may result in positional errors with respect to the engagement of the reels of the tape cassette by the reel drive shafts, that is, the cassette holder may be moved into its operative position when the tape cassette is not completely disposed therein. In such case, the reel drive shafts will have an undesirable mechanical force imparted thereto when engaging with the reels of the tape cassette.